How should we manage patients with interferon-gamma release assay-positive results in rheumatology: assessing the risk and long-term prognosis of tuberculosis

<h2>ABSTRACT</h2><h3>Objectives</h3> Tuberculosis (TB) is a global health problem. Screening for latent TB infection (LTBI) and the administration of preventive treatment in populations at high risk of developing TB are considered crucial. Although patients with rheumatic diseases are at high risk, there are few reports on the screening, prevalence, treatment, and prognosis of LTBI in this setting. In this study, we investigated the characteristics of patients with LTBI in a rheumatology department in Japan. <h3>Methods</h3> We collected interferon-gamma release assay (IGRA) results and patient information from the medical records of patients who attended the rheumatology department at National Hospital Organization Sagamihara National Hospital (Sagamihara, Japan) from 2013 to 2022. <h3>Results</h3> Of 4072 patients tested with IGRA, 157 were positive (3.9%). The rates of IGRA positivity decreased with time (<i>P</i> = .00047), whereas the ages of patients with IGRA-positive results increased (<i>P</i> = .048). The rates of IGRA positivity were higher in patients born before 1960 than those born thereafter (<i>P</i> < .0001). Mycobacterial or imaging tests were performed in almost all IGRA-positive patients (<i>n</i> = 154, 98.1%). Although less than one-third of the patients with IGRA-positive results were treated with isoniazid (<i>n</i> = 50, 31.8%), there was no development of active TB during the average follow-up period of 4.9 years. <h3>Conclusions</h3> In IGRA-positive patients, it is important to perform mycobacterial and imaging tests, as well as long-term follow-up.